This application claims priority with respect to British Application No. 9920311.9, filed Aug. 28, 1999.
This invention relates to apparatus for indicating the load imposed by each axle and/or each wheel of a rail vehicle.
It is necessary to check such loads statically, for example after the assembly of a bogie, because rail track systems impose limits on the weight of rolling stock to prevent excessive wear of the rails. This has previously required a fixed installation, usually a weigh-bridge, to which the bogie must be transported. This is a time-consuming operation, and an accuracy of less than about 10 kilograms is not obtainable. Furthermore with the advent of rail privatisation, it is likely that rail track systems will charge rolling stock operators by the weight of a train instead of by its length as at present, so that the dynamic checking of the loads imposed by all the axles of a moving train will become necessary. It is a time-consuming and costly operation to drive a whole train to a remote fixed weighing installation.
Our U.K. Patent Application No: 9715092.4, now U.K. Patent No. 2,315,559, discloses load-indicating apparatus which is sectional so as to be portable and capable of installation on any length of existing conventional track. The apparatus is rendered sectional by comprising two identical frames which are connectable by means enabling them to be urged apart, the means being disposed at the mid-point of the gap between the rails. This mid-point connection has been found not to provide sufficient rapidity for accurate load indication.
The object of the present invention is to provide sectional load-indicating apparatus having superior rigidity to that of our aforesaid application. A further object is to provide such apparatus which is even more readily portable.
According to the invention, apparatus for indicating the load imposed by each axle and/or each wheel of a railway vehicle comprises two substantially convex carrier shoes adapted to be urged apart into clamped position along the adjacent sides of a pair of rails so as to be engageable by the peripheries of the flanges of the wheels on an axle whereby the tyres of said wheels are raised just clear of the rails, a load-sensing device disposed at the highest portion of each shoe, and load-indicating means connected to said devices, wherein the apparatus is sectional, the apparatus being characterised in that the shoes are adapted to be urged apart into their clamped positions by means of two struts each of which extends between the shoes to enhance the rigidity of the apparatus whilst being readily separable from the shoes to facilitate portability of the struts and shoes.
Each strut preferably abuts, when in operative position, at one end against one of the shoes and at the other end against a nut on a screw-threaded spigot rigidly secured to the other of the shoes.
Preferably, each strut is tubular and fits closely at said one end over a plain spigot rigidly secured to one of the shoes and at the other end over that end of the screw-threaded spigot remote from the other of the shoes.
Preferably, also, each shoe has rigidly secured to it one screw-threaded spigot and one plain spigot whereby both shoes have the same uniform configuration.
Each shoe preferably has at least one carrying handle rigidly secured to it.
Preferably, each device comprises a load-sensing cell fixedly mounted near both of its ends on lands in a recess in the associated shoe, and a load-plate spaced above and rigidly secured to a central zone of said cell, the upper surface of the load-plate being substantially flush with the highest portion of the shoe.
The load-indicating means may be a computer capable of showing and recording the load imposed by individual axles and/or individual wheels.
Alternatively, the load-indicating means may be a digital indicator capable of showing the load imposed by individual axles and/or individual wheels.
Preferably, at least one support member is secured to each shoe so as effectively to embrace the outer and lower faces of the shoe, the or each support member being adjustable in height to suit the cross-sectional profiles of different types of rails.
Preferably, also, two spaced-apart support members are secured to each shoe.
The shoes are preferably provided with replaceable wear-strips aligned with the load-tensing devices for engagement by the peripheries of the flanges of the wheels.